The Continuous Spectra of Flames Containing the Halogens

Abstract

According to the Franck-Condon theory for the dissociation of molecules by light, we should also expect that two colliding atoms may recombine with the emission of light. This should occur if conditions are arranged so that there are appreciable quantities of the free atoms present. Experiments were carried out with flames of chlorine and hydrogen and hydrogen-oxygen flames containing the halogens. Spectra of these flames are found to be continuous extending into the ultra-violet. It is shown that the violet limits of these spectra are in agreement with the hypothesis that they are due to the recombination of the normal and excited halogen atoms. Circulations show that there are enough collisions of this type in our flames to account for the intensity of the light emitted.